Leaking exhaust manifold

[Whimsey]

I have a 2002 F150 with the 4.6 V-8. It sounds like I have a broken exhaust manifold stud at the rear of the drivers side. It's quiet at idle and light throttle cruising. Starting from a dead stop produces the exhaust leak tick as well has heavier throttle. It's annoying but not overly loud. My question is if I don't fix it immediately will I cause harm to the aluminum head. The repair is a bit pricey at this time for me. Base repair is $425 plus shop time hours for removal of broken studs. It could add up. I guess I should have them see how many studs are broken off in the head.

If it's only one I guess it's probably worth it to bite the bullet and have all the studs changed before it costs me more in the future as the other one's break. If multiple ones are already broken waiting probably won't cost me much more. But will I damage the head with the exhaust leak if I do wait?

Thanks

Whimsey

 

[FL_Rob]

Probably only have a crack or blowout in the gasket. It'll sound just as loud.Tear apart no, replace gasket?, yes.

 

[OVERKILL]

Likely broken studs. VERY common. I had three or four broken on mine (can't remember off the top of my head).

Your job sounds expensive? I used an aftermarket manifold, but had the dealer do the work.

Here's what you are up against:

 

[FL_Rob]

So many questions,"The studs changed" ?Removal of broken studs? Are the Ford Heads really that fragile? are you serious or you really dont know know what you're talkin about? Look at the gasket first.

 

[OVERKILL]

Originally Posted By: FL_Rob
So many questions,"The studs changed" ?Removal of broken studs? Are the Ford Heads really that fragile? are you serious or you really dont know know what you're talkin about? Look at the gasket first.


The studs break flush with the head, meaning they need to be drilled, then extracted. Which is really fun, given the proximity of the head to the frame rail and limited amount of space. I attempted the repair myself and then realized it was a much better idea to have it done at the dealer.

 

[FL_Rob]

(just seeing the pics)Whoa ..my correction .ya, I think you have to take all that apart replace everything up to that point, Ford screwed up.

 

[OVERKILL]

Originally Posted By: FL_Rob
(just seeing the pics)Whoa ..my correction .ya, I think you have to take all that apart replace everything up to that point, Ford screwed up.


Yes, they did. Which is why the replacement studs you get are a revised part number, and are stainless steel

Supposed to completely fix the problem. Though doesn't do much to cure the sour taste, as you still have to pony up to cover the repair cost.

My mech at Ford recommended I get the Dorman manifold kit from a Jobber, which I did. Saved me a lot of money, think it was only ~$150?? Then he did the labour at the dealer. The dealer supplied the upgraded studs.

You need a 90 degree drill to get at the studs to drill them out. It is not what I would call an "easy" DIY job, so I was more than willing to have Ford do it.

 

[FL_Rob]

And everyone LOVES aluminum heads!

 

[OVERKILL]

Originally Posted By: FL_Rob
And everyone LOVES aluminum heads!


Yes. I will add, Ford (at least the dealer I use) has a mobile machine shop come up to do any of the high-precision stuff. This includes the manifold stud removal. I have the studs they removed. This is the same machine shop that does the Lock-N-Stitch plug hole insert installs.

 

[FL_Rob]

Holy bucs Batman!!!

 

[bdcardinal]

I wonder if getting a ceramic coating on the manifolds, like you would do with headers would help with the cracking. As often as I sell these manifolds and hardware, it might be a worthy investment for someone to at least try.

 

[Trav]

Quote:
It sounds like I have a broken exhaust manifold stud at the rear of the drivers side


Its not all that common on the drivers side its mostly the pass side rear that let go, check the studs carefully. I've done a lot of these things and they are a huge PITA on the pass side, a left handed drill bit usually brings the broken stud right out if its drilled straight.
On the ones that are intact i blow the heads off, remove the manifold, heat around the studs with a small ball flame and soak with kroil, vice grips will get them out with ease.

Rubber or poly fender well extenders like those found on some Rangers to close the gap between the plastic fender well liner and the frame will stop further rusting.
Because of the location of the front O2 sensors one these engines its a good idea to swap them out while its apart if the truck has close to 100K or more, they are a major pain otherwise.

Quote:
I wonder if getting a ceramic coating on the manifolds, like you would do with headers would help with the cracking.


No but closing the gap between the frame and fender well will slow the rusting significantly, the inner fender wells are to short.
I bought some poly ones but i saw some extenders on a 99 Ranger 4x4 that look like they will work well, maybe you can find a part#?

 

[mechtech2]

I don't think you will damage the head by waiting.
How could it?

 

[FL_Rob]

Burn through ..At least I've seen it on the head to block interface.

 

[morris]

this is just my idea, some may disagree. and there very well could be other ways to do this. i would cote the side of the gasket that goes to the head with anti-seize compound. and use anti-seize on ALL threads. then when you are tightening the manifold dont take to the full torque, stop 10 ft lbs short then after 6-10 days take it all the way. like i said it just my idea. if it starts to leek be for the 6-10 days go ahead and tighten to full torque.

 

[Whimsey]

Originally Posted By: mechtech2
I don't think you will damage the head by waiting.
How could it?


I didn't know, I'm not a mechanic, that's why I asked. I assume then your answer is it will not. Then the only "damage" is to my wallet if it is a broken stud and I wait and more break, a sad but true common problem on the engines, it will cost more to do the repair job. This because of the extra cost getting the broken studs out. I'll check some local reliable indies and see what they charge. Then I'll have the truck inspected to see how bad things are. The problem is on the drivers side, not the more expensive passanger side.

Whimsey

 

[FL_Rob]

Just replace the gasket at this point ...ANTI-SEIZE EVERYTHING.re-install WITH NEW FASTENERS..hope for the best ..Decrease torque by 10 percent.

 

[Trav]

Quote:
The problem is on the drivers side, not the more expensive passanger side.



Not as common but not unknown, there is the EGR tube on that manifold that sometimes rots out right at the manifold fitting.
If you get the manifold done you have to count on replacing the approx $80 tube also.
The drivers side is much easier and takes less than half the time even to drill the studs.

Quote:
a sad but true common problem on the engines


This and spark plugs blowing out together with horrible tensioner rattling puts these engines on my dislike to work on list

 

[Whimsey]

Originally Posted By: Trav
Quote:
The problem is on the drivers side, not the more expensive passanger side.



Not as common but not unknown, there is the EGR tube on that manifold that sometimes rots out right at the manifold fitting.
If you get the manifold done you have to count on replacing the approx $80 tube also.
The drivers side is much easier and takes less than half the time even to drill the studs.

Quote:
a sad but true common problem on the engines


This and spark plugs blowing out together with horrible tensioner rattling puts these engines on my dislike to work on list


If the egr tube rotted would it only make the exhaust tick at throttle appication, or would it be ticking all the time. Or do you mean that if you replace the manifold studs & gasket the tube has to be replaced. At that point in the repair I'd replace the tube to avoid further expense down the road. Thanks.

Whimsey

 

[Trav]

The bung for the EGR tube is directly in the manifold, it will make noise all the time. When they first begin to leak it sounds the same as the stud problem.

99% of the time these tubes break when you try to remove them as they are rotted onto the bung and its rotted into the manifold.
It's in plain sight on the manifold so its easy to check.
Aftermarket manifolds come with the bung but i think you need to order the tube from Ford OEM, i haven't found any aftermarket.